Industrial processing of foam material has advanced to the point of automated production of completed or ready-to-use foam components. Finished foam components are generally in the form of discrete structures which are then installed or otherwise integrated into a subassembly or final product. In products where two or more discrete foam components are to be combined, they are typically held together by a surrounding structure, or by an adhesive. Products which include multiple foam components with complex or differing shapes in multiple dimensions, are necessarily more difficult to assemble, and very difficult to automate the production thereof.
Co-pending U.S. patent application Ser. No. 10/402,612 describes a unitized thermoplastic foam structure which serves as a surrounding structure for an innerspring for a seat or mattress or other support device. Thermoplastic foam structures are unitized by thermal bonding or welding at the interfaces of discrete foam components. As explained in the related application, when thermoplastic foams are used, thermal bonding is preferred over the use of adhesive because the cost and application of the adhesive is eliminated. Thermal bonding however requires controlled application of a heat source at the interface of the foam components. While this can be done manually in various ways, an automated system would be preferable for manufacturing consistency.